Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air insi ....Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air inside leaves based on stable isotope analysis of carbon dioxide and water vapour exchanged between leaves and air. The project is expected to provide fundamental knowledge about how stomata regulate photosynthesis and water use, with significant implications for modelling vegetation function and for improving the performance of crop plants.Read moreRead less
Nitrogen characteristics of plant communities along the North Australian Tropical Transect (NATT). It has become evident that biosphere processes need to be addressed at a global scale to understand global changes. Continental transects analyse ecosystem processes in a global context. The North Australian Tropical Transect (Darwin to Tennant Creek) represents 25% of Australia's vegetation. Biogeological research is underway on NATT ecosystems. Nitrogen availability strongly affects ecosystem pro ....Nitrogen characteristics of plant communities along the North Australian Tropical Transect (NATT). It has become evident that biosphere processes need to be addressed at a global scale to understand global changes. Continental transects analyse ecosystem processes in a global context. The North Australian Tropical Transect (Darwin to Tennant Creek) represents 25% of Australia's vegetation. Biogeological research is underway on NATT ecosystems. Nitrogen availability strongly affects ecosystem productivity, and is of major interest as nitrogen pollution threatens the biosphere. In Australia, nitrogen levels are generally low, but overall knowledge is limited. An integrated ecophysiological approach will relate soil and plant nitrogen characteristics, and provide an analysis of nitrogen relations along NATT. Results will be linked to existing NATT and international transect research.Read moreRead less
Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots ....Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots to absorb atmospheric water could profoundly affect the diversity, survival and productivity of mangroves where high soil salinity limits water uptake by roots, particularly during hot, dry conditions.Read moreRead less
Novel oxygen sensing tools for monitoring the effects of dredging on Australian seagrass communities. Seagrass meadows sustain marine biodiversity and the fishing industries on Australian coasts. Dredging of ports and shipping channels is contributing to their rapid global decline. The project will use state-of-the-art technologies in bio-optics and genomics to create a toolkit for seagrass managers to make informed decisions to safeguard seagrass meadows.
Interactive effects of salinity and nutrients: linking physiological processes with patterns in mangrove forest productivity. The proposed research will provide insight into physiological mechanisms that underpin mangrove productivity along salinity and aridity gradients, and determine how these factors affect plant responses to nutrient enrichment. Plant traits that increase salt and drought tolerance will be identified, thereby assisting development of plant varieties suited to Australian cond ....Interactive effects of salinity and nutrients: linking physiological processes with patterns in mangrove forest productivity. The proposed research will provide insight into physiological mechanisms that underpin mangrove productivity along salinity and aridity gradients, and determine how these factors affect plant responses to nutrient enrichment. Plant traits that increase salt and drought tolerance will be identified, thereby assisting development of plant varieties suited to Australian conditions. The results will also contribute to development of process-based models to better manage mangrove resources with climate change and increasing nutrient influx from urban or agricultural activities. Such models are essential for managing mangrove productivity for sustainable fisheries, and protecting the ecological well being of the coastal zone.Read moreRead less
Will stomatal responses to humidity and carbon dioxide constrain tropical forest productivity as atmospheric carbon dioxide rises? This project will investigate two physiological processes that will partly determine growth responses of tropical forest trees to rising atmospheric carbon dioxide. The project will produce equations summarising physiological responses that can be incorporated into process-based models of tropical forest productivity.
Reading the isotopic archive: carbon and oxygen stable isotope ratios as recorders of plant physiological processes. This project will investigate how plant physiological processes are reflected in stable isotope ratios of carbon and oxygen in plant tissues. Results will contribute towards a mechanistic understanding of the processes that cause isotopic modifications, thereby enabling an improved interpretation of naturally occurring stable isotope signals.
Salinity tolerance along an aridity gradient: linking physiological processes with morphological constraints on leaf function in mangroves. The proposed research will provide insight into the physiological and morphological features that control the productivity of mangrove forests across broad gradients in salinity and aridity. Central to this is this identification of plant traits that increase salt and drought tolerance, which will assist in the development of plant varieties suited to Austra ....Salinity tolerance along an aridity gradient: linking physiological processes with morphological constraints on leaf function in mangroves. The proposed research will provide insight into the physiological and morphological features that control the productivity of mangrove forests across broad gradients in salinity and aridity. Central to this is this identification of plant traits that increase salt and drought tolerance, which will assist in the development of plant varieties suited to Australian conditions. The results will also contribute to development of process-based models to better predict the response of mangrove vegetation to changing climate. A deep understanding of the processes that influence the growth and survival of mangroves is of fundamental importance to sustainable fisheries and protection of wildlife reliant on coastal ecosystems. Read moreRead less
Australia’s native sorghums. This project aims to investigate the biological mechanisms driving the evolution of toxic cyanogenic glucosides by exploiting the natural diversity of Australian wild relatives of the crop sorghum that are adapted to different environments. Wild crop relatives are an important source of traits for improving their cultivated counterparts. Analysing the diversity and evolution of Australia’s 17 native sorghum species will provide new understanding of how plants have ad ....Australia’s native sorghums. This project aims to investigate the biological mechanisms driving the evolution of toxic cyanogenic glucosides by exploiting the natural diversity of Australian wild relatives of the crop sorghum that are adapted to different environments. Wild crop relatives are an important source of traits for improving their cultivated counterparts. Analysing the diversity and evolution of Australia’s 17 native sorghum species will provide new understanding of how plants have adapted to environmental challenges across diverse Australian environments. This should provide significant benefit by providing new resources for plant breeders to produce more climate-resilient crops.Read moreRead less
On the physiology of plant transpiration. This project aims to better understand plant transpiration. It is significant from both a basic and a practical perspective. It intends to solve a conundrum of the biophysics of the evaporative sites within leaves. That is, in dry air, the relative humidity of intercellular air spaces suggests much lower liquid water potentials than those typically measured. At a practical level, the failure to sustain transpiration in dry conditions leads to desiccation ....On the physiology of plant transpiration. This project aims to better understand plant transpiration. It is significant from both a basic and a practical perspective. It intends to solve a conundrum of the biophysics of the evaporative sites within leaves. That is, in dry air, the relative humidity of intercellular air spaces suggests much lower liquid water potentials than those typically measured. At a practical level, the failure to sustain transpiration in dry conditions leads to desiccation and tissue death, and plants differ in this vulnerability. The aim is to apply a novel nanoparticle technique to measure the water potential distribution within the leaf, identify hydraulic resilience attributes, and develop a modern theory of optimal transpiration under varying conditions.Read moreRead less